I love playing TF2 because it's just sooo damn fun and I don't understand why it isn't more popular. what makes it soo special is theres 9 or so classes which are all unique with their own personalities and each one plays so differently that if you get bored you can just switch class and keep switching classes and just never get bored of the game because by the time you've gone through them all then you've forgotten what the first one you played was like.
What I love doing is playing on 2fort (my fave map) and just defending out flag from the enemy. I can just do that for 6 hours at a time and not be bored, then I'll look at the clock and be like "shit it's 3am I better go bed" lol. I havn't come across this is a Online FPS since the days of CS (not counting Planetside) which really just shows you how addictive the game is. There are other modes too like Capture point, arena and the mine cart which all offer something new if you don't like CTF. On top of that theres alot of custom maps which have their own modes that you can easily look for using a custom server browser which is a really nice feature TF2 added.
The animations in TF2 are just pure amazing! I don't know how they make every action look so fluid that it looks like a pre rendered movie but they are just that good. When you see a scout flying in the air, so fast and it all looking totally fluid and life like, when in other games it looks dodgey... you will be amazed! On top of this every class has lots of kool animated emotes and taunts which come with funny voice overs and actions. You can even kill the enemy with taunts which is funny.
The gameplay is just all about teamwork and it's so fast and fun you'll just see explosions and crazyness going off everywhere. Normally in team based games it becomes frustrating because you're on a bad team but with TF2 it just makes the whole experience fun and you'll be working as a team and wont even realise it because you'll find it fun to defend that flag or to heal a mate. TF2 just offers them moments when you'll get a funny kill and then you'll tell everyone about it cause it was so damn great!
The graphics are amazing and you wouldn't ever have guessed that it was on Source because the art style is so different and it just looks so modern. It'll be one of them games that never ages because of it's art style like WOW or Wind Waker. The sound is all fantastic too from the music to all the gun sound effects to all the great voice acted work.
My only fault with the game would be that all classes don't have their achievements yet and by the time Valve finishes them I'm scared they'll ditch TF2 and start developing for other games like they did with CS. However it's not a major thing right now because even with some classes having unlocks and some not, there seems to be no balance issues because Valve has done such a greta job making sure the new weapons arn't overpowered but just alternatives to the current ones with RPGS like stats.
TF2 is pure WIN!
If you don't yet have TF2 then you havn't played Portal or the HL2 series yet so pick up the Orange Box because you'll get them amazing games too and for a low price!
Edit:
I just wanted to do a mini rereview since all the updates and I have to say I prefered the game when it was released. Everything was perfectly balanced and the classes felt right, all done well with no bad weapons. The game flowed really nicely and all it needed really was more maps, which it got and they're great additions to the game. However since the class updates it really ruins the gameplay for the next month while people are grinding away at achievements. The unlocks aswel can be pretty unbalanced and feel very cheap and annoying like say the scouts sandman. So they tried to fix the problem with the timed based unlock system where you randomly get weapons while playing how you want to instead of having to grind out achievements. This is a great idea in theory but you know what I prefer? Just give us the weapons and let us have fun! Or even no new weapons at all because the game was fine how it was. See this time based system now in the game means you get the same weapons multiple times and from other classes you ain't even playing. So it becomes this annoying real time grind where you wait to get them and it make you slowly hate the game.
They've added this inventory system in the game because they want trading and I'm thinking why? Whats the point of having this in and Online FPS? I mean the only people who have these weapons are veterans who play loads. They have everything anyways so why would they ever trade with newer players cause they don't have anything veterans want?
Such a great online FPS ruined.
Edit: 17/01/10
I really like this game again and I'm having a lot of run with the new modes and maps. I still think the whole RPG looting system is a bad idea and the whole waiting to get weapons is annoying. However if you can ignore that then there is one of the best online FPS games ever made! I just can't give it a perfect score anymore because these issues need to be fixed by Valve and I doubt they ever will be. I just think TF2 was a lot better without all the added stuff, but the good thing is you can ignore it all for the most part.